Mirrors have been in existence for years and have been used in interior building applications such as, for example, in bathrooms, as decorations, for furniture, etc., and for exterior applications. Mirrors generally are either (a) first surface mirrors, where the mirror coating is provided between the viewer and the supporting glass substrate, or (b) second surface mirrors, where the supporting glass substrate is interposed between the viewer and the mirror coating. See, for example, U.S. Pat. Nos. 7,276,289 and 7,678,459; U.S. Publication Nos. 2006/0077580; 2007/0178316; 2008/0073203; 2008/0164173; 2010/0229853; 2011/0176212; and 2011/0176236. The entire contents of each of these patent documents are hereby incorporated herein by reference.
Interior mirrors, including home/residential mirrors, are traditionally produced via wet processing, also known as silvering, which allows a highly reflective silver layer and pleasant appearance of the reflected image. However, wet silvering is expensive, and is not environmentally friendly. Silver also is not particularly durable and, for example, is subject to corrosion when exposed to even building interior environments. Durability problems can be overcome with silver-inclusive mirrors, however, by applying one or more layers of protective paint. Yet these paints are sometimes expensive and, at a minimum, inject time delays in the process because they need to be coated and dried and sometimes re-coated and re-dried. Wet coating techniques also are “messy” and potentially hazardous to humans.
Thus, it will be appreciated that there is a need in the art for improved mirrors and/or methods of making the same. Certain embodiments of this invention solve one or more of the problems discussed above.
Certain example embodiments of this invention relate to a mirror having a reflecting layer of or including an alloy of silicon (Si) and aluminum (Al). Such a reflective layer may be used in first surface mirrors and/or second surface mirrors. The SiAl inclusive reflective layer may be sandwiched between at least first and second dielectric layers in certain example embodiments. Certain example embodiments relate to the use of a sputtering target of or including SiAl, in order to sputter-deposit the reflective layer of or including silicon aluminum on (directly or indirectly) a glass substrate, in making a mirror. Heat formable mirrors may also benefit from the use of sputter-deposited SiAl inclusive reflective layers, which material has been found to sustain little or no mechanical damage or optical change during thermal glass bending, even at some small curvature radii. Thus, example advantages of SiAl mirrors include high mechanical durability, thermal temperability (possibly without the need for additional protective overcoat(s)), thermal bendability without cracking, low cost, and environmental stability.
In certain example embodiments of this invention, there is provided a mirror comprising: a glass substrate; a metallic or substantially metallic reflective layer comprising silicon aluminum provided on the glass substrate; the metallic or substantially metallic reflective layer comprising silicon aluminum being located between at least first second dielectric layers, and wherein the first dielectric layer is located between at least the glass substrate and the metallic or substantially metallic reflective layer comprising silicon aluminum; and wherein the layer comprising silicon aluminum comprises, on a weight basis, more silicon than aluminum.
In certain example embodiments, the layer of or including silicon aluminum may comprise, on a weight basis, from 70-99.98% silicon and from 0.02-30% aluminum, more preferably from 75-99% silicon and from 1-25% aluminum, and still more preferably from 85-98% silicon and from 2-15% aluminum.